WASHINGTON, Jan. 24 — Prosecutors in the perjury trial of the former White House aide I. Lewis Libby Jr. paraded a roster of former government officials before the jury on Wednesday to testify that they had informed him about the identity of the C.I.A. operative Valerie Wilson, contrary to Mr. Libby’s claim that he had learned about her weeks later from reporters.
Mr. Libby’s lawyers spent their time cross-examining those witnesses in an effort to attack both their credibility and their memory.
Mr. Libby, former chief of staff to Vice President Dick Cheney, has put the issue of memory front and center in his defense on charges of perjury and obstruction of justice. He is charged with lying to both a grand jury and to F.B.I. agents who were investigating the leak to reporters of the identity of Ms. Wilson.